Interactions between small molecules (or analytes) and proteins or other biomolecules in a cell are fundamental to biology and medicine. For example, many cells communicate with each other via small molecules that interact with cell membrane receptors. Oftentimes, a pharmaceutical compound is administered to a patient because it has some desirable effect, but little is known about how the pharmaceutical compound mediates the effect. While a variety of techniques have been developed to detect interactions between small molecules and individual biomolecules, there are no reliable techniques for identifying the biomolecule or biomolecules in a cell that interact with a small molecule of interest.
Thus, there is a need for a technique that would detect an interaction between a small molecule of interest and a biomolecule (i.e., detect a complex of the two) and permit isolation of the complex, such that biomolecule of the complex could be further analyzed and identified. Such as technique would be useful in the pharmaceutical industry for the discovery of the mechanism of action of pharmaceutical compounds and potential pharmaceutical compounds. Furthermore, such a technique would be useful in the medical field for identifying which pharmaceutical compound may provide the most desirable effects with the fewest side effects for a particular patient. Similarly, such a technique could be used to determine the effects that a pollutant or contaminant may have on an organism.